The umbrella is a very common personal accessory, but the shaft of a standard umbrella is located at the center of the umbrella with the frame being symmetric. The head and body of the user have to thus be on the side of the shaft, and a big umbrella canopy will be needed to cover the whole body of the user.
Due to the fact that the shaft is in the center of the umbrella, if the shaft could be offset from the center of the umbrella, the head and body of the user could be located at the center of the umbrella thereby improving the performance of the umbrella. In other words the off-center umbrella is more efficient than a regular umbrella, even though they both are the same size. Thus an off-center umbrella of a smaller size will be just as effective as a larger standard umbrella.